A third of birds in North America threatened with extinction
State of North America's Birds report finds ocean, tropical birds most threatened
CBC,
18
May, 2016
A
billion birds have disappeared from North America since 1970, and a
third of bird species across the continent are threatened with
extinction, a new report says.
Steven Price, president of Bird Studies Canada, a member of the North American Bird Initiative behind the report, says that since 1970, "the estimate is we've lost at least a billion birds from North America…. The trend lines are continuing down. They have to be turned around or will fall below a threshold where they can be recovered."
Ocean
birds like northern gannets are among the most threatened, a new
report suggests. Many that nest in Canada migrate to the Gulf of
Mexico and were hard hit by the 2010 oil spill.
There are also steep declines in coastal shorebirds like semipalmated and western sandpipers and red knots, which have lost 90 per cent of their population; grassland birds such as the greater sage grouse, Sprague's pipit and chestnut-collared longspur; and aridland birds.
Once
one of the most common forest birds in eastern North America, the
wood thrush has decreased by almost 70% in the last 40 years. Wood
thrushes and many warblers breed in Canada's forests, but winter in
tropical forests of Mexico that are threatened by logging. ((Isaac
Sanchez))
It follows a similar report that focused on Canada in 2012 and found a 12 per cent drop in bird populations since 1970.
But because many birds make very long migrations, Canada's birds are "not really Canada's — they're shared across three nations," said Price.
For example, northern gannets nest in four colonies on Canada's East Coast, but migrate to the Gulf of Mexico, where they "got hit very hard by the Gulf oil spill" in 2010.
Waterfowl
such as wood ducks are making a big comeback due to wetland habitat
protection and hunting restrictions. (Sean Kilpatrick/The Canadian
Press)
Wood thrushes and many warblers breed in Canada's forests, but winter in tropical forests of Mexico that are being logged.
Many grassland birds rely on habitat that run from Canada's Prairies down to Mexico's Chihuahuan grasslands — nearly 70 per cent of birds that migrate between the northern and southern grasslands have disappeared since 1970.
"It's our North American Serengeti," Price said of the region. "We have so many endangered birds or birds in decline because we have really dissected and divided the grasslands and prairies."
Some birds also face domestic threats — many coastal birds on the Haida Gwaii islands on Canada's West Coast are threatened by invasive predators such as raccoons and rats. They include species like the ancient murrelet, Cassin's and rhinoceros auklets, the fork-tailed storm petrel and the black oystercatcher.
The report did have some good news. Populations of waterfowl such as wood ducks and canvasbacks and birds of prey such as the osprey and peregrine falcon continue to rebound. Wetland habitat protection, hunting restrictions and bans of pesticides such as DDT have helped bring them back.
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